This is undoubtedly a scam. The service claims to provide the identity of people who search for you on Google, Yahoo, Bing or AOL, or check your profile on Facebook, MySpace, Twitter or Digg. To test it, I signed up under several fake names and email addresses, all of which cannot be repeated in polite company. (Try it yourself.)
Each time, it claimed at least 50 people had searched for me or checked my profile within the last few days. However, to obtain their identities and locations, I had to providey my credit card info and pay $1 for the first day, with an automatic renewal for $49.97 a month unless cancelled. I did not provide my credit card info, but if you do, all I'd say if you try to cancel and get your money back is Good Luck!